Gotta love fall...

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Feb 6, 1998
11,759
Canadian Sailcraft 36T Casco Bay, ME
Just came back to the mooring after a beautiful little sail. Winds were brisk, temp around 38F - 40F but the wind chill was kicking... While I am still wearing shorts and flip flops my legs and feet are fine... I had my down sweater on but forgot my winter hat... My ears feel like they could shatter....

What an amazing time to be out on the water enjoying the best winds of the year. Last night temps dipped into the mid 20's and tonight they will dip into the low 20's. Trying to push it for thanksgiving weekend on the boat but may have to drain the fresh water system before then because the marina hoses shut off in a couple of days..

Before I headed out this morning I had to change my glow plugs. I fried them all with the Li battery bank. This was a real Duh' moment on my part........:doh: Li batteries don't suffer from voltage sag, like lead acid batteries do. While EVERYTHING ELSE appreciates the lack of voltage sag, and loves it, the glow plugs do not...

The 10.5V glow plugs rely on the voltage sag of lead acid batteries so as not to cook themselves... I had still been using my 15 second press from the lead battery bank and all I need is about 3-4 seconds with the Lithium bank.. ;) Doh'...... Next week I will install a diode in the glow circuit to drop the voltage to the glow plugs just in case I press longer than I should....

Fortunately the glow plugs take about 5 minutes to swap out, for all four, and only cost me $6.41 each.. Westerbeke of course expected me to pay them $85.00 for each glow plug.... Like that's going to happen...........:D:D

I got all four for less than 1/3 the price of just one from Westerbeke..... Also ordered a full spare set while I was at it and I still never got to the cost of one glow plug from Westerbeke. Eight NGK glow plugs for $51.28 or less than the cost of 1 "red glow plug", not bad......;)

The best part of all this is that I am now sitting in the cozy cabin at 72F, actually a little too hot, listening to tunes and doing some invoicing.....

Amazing day....
 

FB111A

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May 4, 2013
36
Pacific Seacraft Crealock34 Belfast, Maine
Finished winterizing on the hard yesterday. Went to haul in my dinghy,got my hands wet/numb. It is a lovely day for a sail today, I must be a wimp for hauling so soon, especially since I still have plenty of propane aboard.
 

CalebD

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Jun 27, 2006
1,479
Tartan 27' 1967 Nyack, NY
What is it with "marine" engine parts suppliers?
Why do they feel they should bilk their customers for small stuff like glow plugs & injectors?
I found a similar, if not more egregious markup on glow plugs for a Universal engine at Torreson marine: nearly $90/glow plug. For a 3 cylinder engine that would be $270.
I found the same glow plugs at a Kubota dealer for < $9/glow plug. Is that a 1000% markup? Astounding!
Care to share your source for Westerbeke parts for other unsuspecting owners?
 
Feb 6, 1998
11,759
Canadian Sailcraft 36T Casco Bay, ME
What is it with "marine" engine parts suppliers?
Why do they feel they should bilk their customers for small stuff like glow plugs & injectors?
I found a similar, if not more egregious markup on glow plugs for a Universal engine at Torreson marine: nearly $90/glow plug. For a 3 cylinder engine that would be $270.
I found the same glow plugs at a Kubota dealer for < $9/glow plug. Is that a 1000% markup? Astounding!
Care to share your source for Westerbeke parts for other unsuspecting owners?
My glow plugs came from NAPA, special order.. You just need to cross reference them. Get creative with google and there's not much that can't be cross referenced...
 
Jan 30, 2012
1,154
Nor'Sea 27 "Kiwanda" Portland/ Anacortes
Maine Sail

Can you explain briefly normal "voltage sag" and how your diode-to-glowplug solution ends up reducing the voltage at the glow plug when the 12 v source is a Li battery ?

Charles
 
Feb 6, 1998
11,759
Canadian Sailcraft 36T Casco Bay, ME
Maine Sail

Can you explain briefly normal "voltage sag" and how your diode-to-glowplug solution ends up reducing the voltage at the glow plug when the 12 v source is a Li battery ?

Charles

When a large load is applied to an LA battery the voltage dips or sags. Most glow plugs for 12V systems are rated at 10.5V to compensate for the voltage sag and still get hot enough. Most of these engines are industrial or tractor engines where a single small battery is used.

The usual rating for these plugs is a 15 second duration. While they can survive at voltages above 10.5V they don't do well at all when the voltage does not dip at all and exceeds the voltage of LA batteries.. With an LA bank you would normally start at 12.6V or so with a full battery but with a 40A+ load the voltage may dip into the low 12's, depending upon bank size, age etc...

With a single starting battery, as used on tractors, the voltage may sag to the mid 11's... My Li bank hoovers at about 13.35V even when the four glow plugs are loading it. Because of this a considerably shorter glow plug push duration is required. As I found out today 3 seconds at an engine block temp of 34F was more than enough with the Li bank and the engine fired up in about 1 second.... With my old LA bank it required the full 15 seconds at these temps and it cranked for perhaps 2 - 3 seconds.....

I will be installing perhaps two diodes in the B+ for the glow circuit which will help drop the Li battery voltage at the glow circuit by 0.6V - 0.7V, for each diode. If I install two for a 1.4V drop I will be at about 12V to the glow plugs which is far safer than 13.35V +/-...

This way if I should ever forget and push the glow longer than necessary, force of habit thing, the voltage will not be high enough to damage them. It would still leave me with enough voltage to start off my AGM reserve battery if I use a slightly longer push...
 

Rick D

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Jun 14, 2008
7,204
Hunter Legend 40.5 Shoreline Marina Long Beach CA
Oh By The Way...

...it sounds like beautiful weather even given the temp. The photo on page 5 of PS is gorgeous! What time of year was it taken? The letter about alternator install was informative as usual.
 
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